Stoker.



Dir. CRAWFORD.

STOKEB..

q:10br FILED MAY 3.1909.

APPLICA Patented Mar. 9, 1915.

Mmmm,

Il P. CRAWFORD.

sToKER.

LLQ

APPLICATION FILED MAY 8,1909.

Pfbewted Mar. 9, 1915 4 SHEETS-SHEET 2.

D. F. CRAWFORD.

STOKER.

APPLICATION FILED MAY 8,1909.

4 .-Lll, I Patented Mar.9,1915.

4 SHEETSYA SHEET 3A @INVENTION D P. CRAWFORD.

STOKER.

APPLICATION FILED MAY s, 1909 Patented Mar. 9, 1915.

4 SHEETSSHEBT 4,

WITNESSES INVENTOR tlpectieetien of Letters Patent.

Patented Tiller. 9, 1915..

applicaties. inea e, ieee. serial no.

To all whom, may comerse:

13e it known that li, Davie ll". CRAW- ronn, a citinen of the United States, residing' at Pittsburgh, in the county of Alle gheny and State of ennsylvania, have in vented certain new and useful `ln'iprovements in Steigers, of which the follewing is a specification.

The invention relates to automatic underfeed stokers, and has for its primary oloiects; the provision in apparatus of the character specied of improved means for regulating the feed through the feed trough; the provision of auxiliary feeding means in the trough whereby the supply of fuel to different 'portions thereof may loe governed independent of the main feeding device; the provision of means whereby the stroke and feed of the auxiliary feeding means may be adjusted independent of the main feeding device; and the provision of an improved form of supporting means for the inner ends of the grate bars. Certain embodiments of the invention are illustrated in the accompanying drawings, \vherein:

Figure 1 is a longitudinal section through ya furnace supplied with the improved Stoker,

Figure 2 is a partial plan view of the apparatus,

Figure 3 is a section through the trough on the line llf-lll of Figure 1, I

Figure 4l is a side elevation of he upper edge of the trough, showing the grate sup porting frame,

Figure 5 is a p artial longitudinal section through the end of a. trough supplied with a modified forni of plunger feed,

Figure 6 is a rear end elevation of the apparatus,

Figure 7 is an enlarged detaill side elevation of the connection between the operatshown as is necessary to illustrate the rela tion of the parts.

Referring first to the general relation of parts as shown in Figs. 1 and 2; 1 is the iirebox; 2 is one of the side grates which may be of any approved type, it being un derstood that the other side grate, not shown, is of the same construction; 3 is the front grate; vv1 is the drop grate located at the end of the side grate 2, which drop grate is preferably somewhat inclined to the rear as indicated in dotted lines in Fi 1; and 5 is the underfeed trough prefere. ly of the general contour indicated in Fig. 1.

The rimary feeding member is the piston 6 whicl is mounted for reciprocation beneath the hopper and is operated from the shaft 8 by means of the cranks 9 9 and the connecting rods l0--10. rlhe shaft is oscillated from a .steam cylinder 11 at the side of the irediox oy means of the crank arm 12 keyed to the shaft 8 and connected at its other end to the piston rod 13 of the steam cylinder.

Secondary or auxiliary feeding means are provided for the trough in the forni of the two pistons or plungers' 141- and l5 Working in the manner indicated in 1, and arranged in tandem. The plungers are pivotF ed to the connecting rods 16 and 17, Which connecting rods are pivotally secured at their other ends to the adjusting hars or links 18 and 19. The links 18 and 19 are operatedfrom the shaft 8 hy means of a crank 20, which crank is provided on each side with two projecting pins 2l and 22 (Fig. 7). T he links 18 and 19 are provided upon their opposite faces with notches or recesses which are adapted to engage the pins 21 and 22. lil/hen the links engage the lower pins QQ a. short stroke of the pistons or plungers is secured, and when the links are shifted upward to engage the pins 21 longer strokes are provided. The plurality of notches provides for a shifting of the position of the pistons or plungers l'iackward or forward, a backward shifting of the pistons securing a less ,effective stroke as a smaller portion of the pistons is in this case foi-rrd into the fuel in the trougl'i. The shifting also changes theposition of supplemental feed.

"lhe discngagng of the links from the pins in order to secure an adjustment is accomplished hy means of thc mechanism illus trated in detail in Figs. 7, 8 and 9. As here upper edges ofthe esstin shown, each of the hersfiend i9 is engaged by loopsor eolisrs 23 end 2li. These eoliors ere pivotnliy engaged hy crank arms 2e end'- 26 carried hy the tube 2'? .end the rod respectively. is indicated ih Figs, 6 end 8, the .rod and tuhe are extended ieterily sind provided et their ends with the open ating ievers 29 and 30. These handles ere extended shove the hoor of the oeh and ere prrmide-d4 with operotinghotohes 3i adopted to engage notehes in the rech interpoeed between the 'tivo handles. The cetehes'ere operated :from the upper ends oi the hendies'hy ineens of suppienientei heudies provided with connecting rods indieeted inign e,

The ends o'fgihe grote here the gratos 2 end i ere pivototiy supported at their ende upon castings 34; iiinetrete'd in Fi s.. A3 end e., which costringe ere riggidiy 'bei to. the upper edges o the trough hy means of studs 'or boitel extending through the ,downwardly ,protesting The 3iore recessed for thelreeeption of the ends of the grote here, end the arrangement not oniy adds to the rigidity of the trough. et edges, het oise permits of the ready removal of perte for renewei or repen.

in some instances muy he desirehie retard the forward feed to the re i' end of the trough, in which' euseA the -e-riungenient shown inifig, mey he empioyed, in this construction the .piston i5? empioyed dires-ted reervmrdiy instead of orwurdiy es in the other forni of device, und is reeiprof vhated from theeonneoting rod it" hy ineens of the iinh 36 which is mvoted to the piston and to the rod i6. This beohward feed im tarde the forward movement of the eoei, and es e resuit the ooei is banked up in front of the piston 15 and caused to spread ieteruiv,

Still another modification is iiiustrated in. Figi 10, which modification difiers from that of ig. i in that .onlyv e single piston 15" is empoyed'in the trough 52 instead of the of pistons. VThe eonstruotien in other respente is the seme throughout es that heretoforo described for the form of Fig. l. In this connection it will he understood that the invention is not restricted es to the number of auxiliary feeding piangere, but that any number may be used depending upon the conditions.

oonstituting it Wiii he seen `from the foregoing that the feed through. the. trough may be much more eeeurstey 'governed than'in the old type of construction, wherein s single piston feed at the. rear was dependedl upon to supply the fusi throughout the length of the furnace. The amount of hand firing necessary is very :much reduced, es. the tendency of the coal in any portion of the trough to bank and oistrihute unevenly muy be overcome by the operation of the pistons ld and l5, which pistons may he operated with. e, long or short stroke, depending upon the requirements, onu may he entireiy stopped if desired, by pissing thehars 18 and 19 midway between the pins 2l and 22. The pistons or plungers also serve to agitato the fuel, thereby hremlring up the mass which muy otherwise become compacted and thus securing notonly o better forward feed, but also a better upward and ieteral spreading. am aware that rods provided with ugitators have heren tofore been used in underfeed troughs, but such egitetors dinger from my feed plungers tout the;7 do not produee a positivo orwrd feed, out on each reverse stroke carry inei roervvardiy. They are furthermore eoohio omdjustment without removing woody or' corti in the trough, :is opposed v construction wherein the position und iength oiz stroke may be adjusted at any time to suit requirements.

Hoving thus described my invention and iiiustrsted its use, What I claim es new' and desire to secure hy Letters Patent is the 'oiiowing in combination in an underfeed Stoker, a feed trough, u reinforcing member along; the side edge of the trough and overlapping the top thereof and provided with recesses for receiving the ends of grate bars, Ineens for detaehebly securing the reinoroingrnomher to the edge of the trough ond ugrinst movement thereon, and grate here constituting u side grate and having their inner edges supported in the said re` cesses.

In testimony whereof I have hereunto signed my nume in the presence of the two subscribed Witnesses.

DAVXD F. CRAWFORD,

iirNNArnn, Conor, 

